1. Size: 4-1/2"~20"
Steel grade: J55, K55, N80, N80Q, L80, P110, C95
Thread Type: LTC, STC, BC
Standard: API SPEC 5CT\API SPEC 5B
Length: R1, R2, R3 or fixed length
2. Quality control
We have implemented stringent quality control tests system to
inspect raw materials and examine products in every stage of the
production:
* Size and surface inspection
* Non-destructive test
* Thread inspection
* Hydrostatic test
* Drifting test
* Physical and chemical analysis
* Hardness and pressure test.